Comparing with a liquid crystal display (Liquid Crystal Display, referred to as LCD), an organic electroluminescence diode device (Organic Light-Emitting Diode, referred to as OLED) has the advantages such as thin, light, broad angle of view, initiative luminescence, continuously adjustable emitting color, low cost, fast response speed, low energy cost, low driving voltage, high emitting efficiency, broad working temperature range, simple production process, and flexible display or the like, which is greatly attended by the industry and the science world.
The basic structure of OLED comprises an anode 20 and a cathode 30 provided on a base substrate 10, and an organic material functional layer 40 provided between the anode 20 and the cathode 30. In order to improve the light output ratio of OLED and reduce the emission loss on the surface of the anode 20, as shown by FIGS. 1(a) and 1(b), a transmission enhanced film 50 may be provided between the anode 20 and the base substrate 10 or provided outside the base substrate 10, to reduce the reflected light using the interference of the thin film, so as to improve the light output ratio.
In addition, when the base substrate 10 is a flexible base substrate 10, because the surface roughness of the flexible base substrate 10 is generally larger than the surface roughness of the glass base substrate, in the case of bending, the breaking or the peeling off of the film layer provided on the flexible base substrate 10 is very easily caused due to the uneven and the stress effect of the surface of the flexible base substrate 10. In order to solve the flatness problem between the flexible base substrate 10 and the film layer, a buffer layer 60 is generally provided between the flexible base substrate 10 and the film layer. The buffer layer 60 has a stronger adhesion to the flexible base substrate 10 and the film layer. Such a buffer layer 60 comprises various types, wherein the most important ones are materials having a photo-crosslinkable group, such as a photoresist. The high molecular structure formed by this material through ultraviolet curing is not only helpful for improving the surface flatness and the adhesion of the flexible base substrate 10, but also helpful for improving the water-oxygen permeation resistance.
In the prior art, an OLED display panel using a flexible base substrate 10 should be provided with a two layered structure of a transmission enhanced film 50 and a buffer layer 60 at the same time to achieve the function of improving the surface flatness of the flexible base substrate 10 and to improve the light output ratio. However, it may result in the complication of the production process for the OLED panel.